Prior-art anesthetic metering systems, e.g., that described in EP 0 449 545 A1, have, in general, an anesthetic evaporator with an associated reservoir with a liquid anesthetic reservoir. Such reservoirs are usually installed permanently at the anesthetic evaporator and are refilled according to relatively complicated and time-consuming techniques with a filling tube, a filling adapter or a funnel. The fact that part of the anaesthetic added during refilling is easily spilled and unintendedly burdens the persons present due to evaporation into the ambient air is especially disadvantageous.